package com.shimakaze.reggie.controller;


import com.shimakaze.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则请求结束后会被删除
        log.info("已上传文件:{}",file.toString());
        //原始文件名
        String originalFileName = file.getOriginalFilename();
        //截取后缀名
        String suffix = originalFileName.substring(originalFileName.lastIndexOf("."));

        //使用UUID重新生成文件名，防止重名文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix;

        //创建目录对象
        File dir = new File(basePath);
        //目录不存在时创建目录
        if(!dir.exists()){
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     * @throws IOException
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        FileInputStream fileInputStream = null;
        ServletOutputStream outputStream = null;
        try {
            //通过输入流读取文件
            fileInputStream = new FileInputStream(new File(basePath + name));

            //通过输出流将文件写回浏览器
            outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
        finally {
            //关闭资源
            if(fileInputStream != null) fileInputStream.close();
            if(outputStream != null) outputStream.close();
        }
    }
}
